This invention relates to a geochemical exploration process. It is particularly useful in locating subterranean deposits of petroleum materials.
Numerous geochemical exploration processes have been previously proposed. U.S. Pat. No. 2,406,611 (filed over 35 years ago) describes advantages of sampling ground waters rather than soil samples, rock samples, open-water samples, or connate water samples. The use of the ground waters avoids variations in the adsorption of hydrocarbons on solids, contaminations or interactions of hydrocarbons with atmospheric gases, etc. The patented process used ground water samples that were stored in containers for later analysis in a laboratory. U.S. Pat. No. 3,345,137 (filed about 25 years later than the above patent) indicates that bacterially induced chemical changes often significantly alter the hydrocarbon concentrations of ground water samples that are stored for even a few days. It describes an improved process in which a bactericide is added to the samples and concentrations of C.sub.2-5 and C.sub.6-7 hydrocarbons are plotted separately.